Silent type-bar action



C. SPIRO SILENT TYPEBAR ACTION Dec. 20, 1927.

Filed y 29. 1926 Patented Dec. 20, 1,927..

' UNITED STATES.

' CHARLES SPIRO, or nnw YORK, N. Y.

1,653,316 PATENT SILENT,.TYPE-BAR ACTION.

' Application filed Ma -29,

actuating connections which reduce the type bar speed as it approaches the printing point. Such a connection involvesthe use of numerous joints and requires a. material pressure on the key in initiating the typebar movement. 1 J

. It has been found particularly desirable'to provide for a silent action of the usual pivoted front strike typebar actuated by a lever with a pin and slot connection to the typebar. In prior constructions of such a connection the relation of the pin oft-he] actuating lever to the typebar slot is such that the lever continues its pressure upon the typebar even after it has reached the printing limit of itstravel which results in a very noisyimpact with the platen, or with an abutment member if used.

To obviate such objections and efiect the improved results desired, I have provided an actuating lever having its pin,'operating in the typebar slot, so disposed as to traverse I an arc tangential to the longitudinal ax'isof.

the typehar slot at the printing limitof its movement, whereby no pressure can be transmitted to the typebar'iafter its printingimpact withthe platen. For this purpose the radius of the actuating lever is shorter'than usual so that the curve of acceleration is 1 greater, and after the peak isreached the as the lever pin approachesthe axis of the typebar. After passing the mid-stroke po sition thtlev 'eincreases with consequent untilthe parts reach ape ,tive. to its actuating lever.

1926. Serial No. 112,557.

sition at the end of the stroke where a plane through'the pivot and pinof the actuating lever lies at substantially a right angle to the longitudinal axis of the typehar slot and no further movement can be transmitted to the typebar. This positively controls thetypebar travel independently of the pressure ap'pliedupon thekeylever as at the end of its travel the actuating lever not only ceases to impel the typehar but holds it against further forward or rebound motion.

It is'also important in the assemblage of this inventionto provide actuating levers onwhich the typebar connections are equallyi spaced from the lever pivots in order to effect an even leverageat allpoints inthe arc of the typebarcsector. This involves the use of sub-levers connectedto the key levers and having vertical arms at successively different. elevations from which connecting ligaments extend to the actuating levers ina plurality of horizontal planes.

-The invention has for an object to provide a novel and lmproved construction wherein the connection between theactuating lever and typebar is so disposed that no pressure i is transmitted from one to the other as the typebar reaches the printing point.

Another, objectof the invention is to present a new typebar action including a piv- OFFICE,

oted typebar and an actuating lever therefor having a pin and slot connection in which the arc of travel of the pin is disposed tan I gential to the longitudinalaxis of the slot of J the typebarwhen the typebar is in'printinfg position,wherehy the bar is brought to rest and there held against movement rela- Aiurt-her'object of the invention is provide a typehar action including a slottedtypeb ar and actuating lever having a conneeting member disposed so that a plane extending through said member and the pivot of the lever will lie at a right angle to the longitudinal axis of the slot of thetypebar as the bar approaches either limit of its travel, which prevents the application of vfurther power to the typebar and retains the same in either its position of rest or print ing position. I

The invention also-presents a uovelcom by maximis ng;aiapssealigamem Like numerals refer to like parts in the several figures of the drawing.

In the application of this invention I use instrument-alities common in the art,- but so proportioned and arranged as to effect the novel function of relieving the typebar from pressure upon its printing engagement at the platen. A, desirableiorn'i of the inventionis herein disclosed and comprises the key lever pivoted at 11 and normally elevated into engagement with a stop 12' by the spring 13. The downward travel: of the lever may be limited by the usual stop, while a vertical extension 15 from the lever carries a pin 16 disposed in the slot-ted arm 17 oi: the sublevcr 18. The series oi these levers are pivoted in a single horizontal plane and the vertical arms thereof vary in length from this pivot 19 for the suiblevers so as to disperse the pivoted connecting ligaments 20 in a series o'tparallel horizontal planes. The ligaments are connected at subtantially the midlength of the actuating levers 21 which are of equal operative length to etlect an even leverage upon each typebar 22. The levers 21 are pivoted at upon a segment 28 arranged concentric to the segment 29 of the typebar pivots 2st, and theconnecting pins upon said levers are each disposed at an equal distance from the pivots 23 so that the pressure at the printing point of each typebar is relieved to insure silencing. This is also facilitated by the sublevers of different heights and the connecting ligaments in parallel horizontal planes 'to avoid angle distortion and apply a direct motion to the actuating lever. r

The elements ust described: are duplicated for the several units of the action that the operation oi: only one of the actuating levers will be described. This lever" is provided with. the connecting pin or similar member 25 operating in a slot 26 in the tail 27 of: the typebar 22, and such pin is located at" a distance from the pivot- 23 of the. actuating lever :50 that-as it approaches either extreme of its movement its arcof travelis tangential to the length'o'r longitudinal axis of the slot 26: The radius otthe pin is therefore less than inthe'usual typebar action and the pin appliesno pressure to. the

typebar at either end of the lever stroke but acts tohold the typebar againstany relaplaten30 with only sufficient force to produce the desired imprintand avoids a violent impact producing noise and injury to the type or platen at this point.

Referring to Figures 2, 3 and i it will be noted that the plane 0-0 through the pin and pivot of the actuating lever lies at sub stantially a right angle to the longitudinal axis (F d of the typebar slot at either limit of movement or position of rest, and if such lever be straight the length of the lever extends at the angle stated. reducing the usual distance of the pin: from the pivot of the actuating lever so that it will'travel in an arc aa intersecting the are b-b which is the path of the outer end of the typebar slot. These arcs join at the oppositepoints of rest where the arc a-a lies tangential to the axis (Zd and the are 6 is tangential to plane c-.c so there can be np further movement in the previou s di rection; of travel, and the typebar is retained or locked against any movement in either direction relative to its actuating lever.

This construction provides for an easy starting of the stroke from the rest position of Figure 2 by applying the greatest leverage to the typebar at that period and gradually reducing the leverage and increasing the speed until the pin of the actuating lever reaches its point of travel nearest the typebar pivot, as in Figure 3. From this point the speed decreases as the leverage increases to apply more power until the position is reached at the end of the stroke where no pressure is applied to thetypehar at'the printing position of Figure 4. The result is the practical elimination of the hammer blow and the: impact of the type is only suliieient for the printing purpose.

This results in The pressure at this impact can be varied as found desirable for different classes o1 work by a proper relative adjustment of the pin and slot conneetion at the typebar. It will also be oh vious that such connection may be reversed, that is, thepin located upon the typebar in stead of thelever, and that the contour of the cooperating slot may be varied. The actuating lever'supports the typebar when at rest without the use of the usual member upon the frame for that purpose, as with the parts in the dotted line position of Figure 1, the typebar is locked and supported against downward movement by the pin of the actuating lever positioned relative to the slot of the typebar, as in Figure 2. This locking of the typebar against motion relative to its-actuating lever prevents chattering or rebound from its, position of rest which is liableto reduce the speed of operation through collision, with anfadjacent bar starting to move, or the holding of the carriage feed 'dogs from completing their operation for letter space travel. At each limit ard typewriter constructions. While the de tails of the invention have been specifically shown and described, the invention is not confined thereto, as changes and alterationsmay be made without departing from the spirit of the invention as recited lowing claims. I I

What I claim is 3 1. In a typebar action, a pivoted typebar, an actuating lever therefor having a pinand slot connection with the typebar in which the pin engages a wall of the slot to continuously apply power to the typebar up to the in the fol- 7 point of printing impact and thereafter remains inoperative upon said slot wall to further rotate the typebar, and a key le'ver op eratively connected to said actuating lever.

2. In a typebar action, a pivoted typebar, an actuating lever therefor having a pin and slot connection with the typebar in which the pin engages a wall of the slot to continuously apply power to the typebar up to the point of printing impact and thereafterre mains inoperative upon said slot wall to further rotate the typebar, said pin being disposed to engage a slot wall at the opposite extreme of travel of the typebar to support the same at its position of rest, and a keylever operatively connected to said actuating lever.

3. In a typebar action, a pivoted typebar, a pivoted actuating lever therefor having a pin and slot connection. with the typebar in which the pin engages a wall of the slot to continuously apply power to the typebar up to the point of printing impact and thereafter remains inoperative upon the slot wall with the arc of travelof the pin tangential to the longitudinal axis of the slot, and an operative-connection from the key lever to move the pin of the actuating lever in an arcuate path.

laIn a typebar action, a pivoted typebar having a slotted tail, a pivoted actuating 1e- ;ver having a pin traversing an arcuate path within the slot of said tail to continuously apply power to the typebar up to the point of printing impact and thereafter remain inoperative upon theslot wall to further rotate the typebar, the lonigtudinal axisof the lever being then at a right angle to the lon gitudinalaxis ofthe slot,and a keyflever operatively connected to said actuating. lever. I

'- 5. In a typebar action, a slotted typebar,

an actuating lever having a pin disposed in said slot to traverse an are opposite to the arcuate path of the outer end of the slot, said arcs intersecting when the typebar is at the printing impact position to prevent further application of power from the pin to the slot wall and also intersecting when the typebar is at its opposite rest position, and a key lever operatively connected to move the )in of the actuatin lever in an arcuate )a-tln 6. In a typebar action, a series of typebars pivoted upon a segment, a series of actuating levers pivoted upon the segment concentric to the typebars and having pin and slot connections therewith disposed at equal distances from the lever pivots with the pins positioned to continuously apply power to the typebar up to the point of printing impact and thereafter remain inoperative upon the slot wall to further rotate the typebar,

sub-levers pivoted in a horizontal plane and having vertical arms of different heights, ligaments connecting said arms and actuatlng levers, and key levers operatively connected to said sub-levers.

In testimony whereof I aflix my signature;

CHARLES SPIRO. 

